PVC injection molding plastic resin -4

Due to the special properties of the PVC material, special PVC injection molding machines should be selected for production. Please note the following points:

•  - The screw length to diameter ratio should be 20:1, and the compression ratio should be controlled between 1:1.6 and 1:1.2.

•  - The screw and nozzle should be specially made and chrome-plated for the PVC material.

•  - Injection pressure, speed, backpressure and temperature can be multi-stage and precision controlled. 

Last but not the least, the following requirements should be noted in the preparation of raw materials:

•  - It is necessary to prevent the raw PVC material from being mixed with other plastics, or PVC degradation might be caused. Especially, when the machine has worked with other raw materials, it is necessary to clean the barrel and the screw before molding the PVC product. (Clean the screw and barrel with the PS plastic)

•  - Before shutdown, the PVC material must be completely cleaned. If it needs to be stopped for a long time, to prevent the PVC from corroding the machine, the screw and the barrel should be cleaned with PS.

•  - When the PVC injection molding material is put away for more than 6 months in a hot and humid environment, it should be dried for 1-2 hours under the 60-80°C temperature conditions before use.

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